1. Field of the Invention
This invention is generally relates to a shield structure for use in an electronic apparatus, and more particularly to a shield structure of reduced size and which lightens the electronic apparatus.
2. Description of the Related Art
Referring to FIG. 19, a conventional radio communication apparatus includes a first housing 10, a second housing 20, and a printed circuit board 30 (called PC board hereinafter). Many components 31 are mounted on the PC board 30. A male screw 40 is fitted to a female screw 12, thereby the PC board 30 and the first housing are fitted to the second housing 20.
To shield the components 31, some shield structure are used in the conventional apparatus. FIG. 20 shows the conventional apparatus using a conventional shield structure. A partial view illustrated by one dot line A is shown in FIG. 21. A conductive layer 21 is plated on an inner surface of the second housing 20.
A first ground pattern 32 is printed on a surface of the PC board 30, while a second ground pattern 33 is printed on another surface of the PC board 30. The second housing 20 has a protruding portion 22.
When the first housing 10 and the PC board 30 are fitted to the second housing 20, the protruding portion 22 is urged toward the first ground pattern 32 and thereby contacts the first ground pattern 32. This structure enables the components 31 to be shielded by the conductive layer 21, the first ground pattern 32 and the second ground pattern 33.
Further,to enhance the connection between the conducive layer 21 and the first ground pattern 32, the conducive member 23 may be provided between the protruding portion 22 and a first ground pattern 32 as shown in FIG. 22.
In the above two conventional apparatus, the second housing 20 includes a resin member 26 and the conductive layer 21. The resin member 26 is molded by a resin mold injection method. After the resin member 26 is molded, the molded resin member 26 is transported to a conductive layer plating process. While the molded resin member 26 is transported to the conductive layer plating process, it is necessary to transport the molded resin member 26 carefully so that the molded resin member 26 is not injured.
Further, in the plating process, it is necessary to mask a predetermined area of the inner surface of the molded resin member 26 so that the conductive layer 21 is plated to only a portion other than the predetermined area. Therefore, it is troublesome to mask the predetermined area. Accordingly, this troublesome process causes high cost.
Furthermore, when the radio telecommunication apparatus is out of order and is to be disposed, it is not so easy to separate the conductive layer 21 from the molded resin member 26. Therefore, this structure is not suitable for the disposal of the housing 20, that is to say, this structure is not suitable for recycling the housing.
A third conventional structure is shown in FIG. 23. A housing 20A, as shown in FIG. 24, is made of resin material. The components 31 are shielded by each of a plurality of conductive shield cases 34. A partial view illustrated by one dot line B is shown in FIG. 24. Each of the shield cases 34 is attached to the first ground pattern 32 on the PC board 30 by soldering.
In this structure, it is troublesome to solder the shield case 34 to the PC board 30. Further, since the space between the shield case 34 and the housing 20A is needed, the third conventional apparatus becomes large in size and heavy in weight.